This may be a similar angle like the shirtless Avon head. Two things to notice:1) The left neck line, i.e, Avon's right, is vertical below the corner end of his mouth, not below the middle of the chin or center chin point as in the shirtless Avon head; and2) There is a shadow under his chin, because the muscle or line slants down in a hypotenuse from the chin tip to the vocal chords, since people usually don't raise their tongue in a prolonged glottal stop letter K right angle position.You can use a ruler, finger, pencil, or edge of paper to line things up vertically, horizontally, and diagonally.